Chapter 30

Does pressure-induced melting explain ice skating? Suppose an ice skater weighs $m=70\mathrm{kg}$. An ice skate exerts a pressure $\mathrm{\Delta }p=mg/A$ on ice, where $A=1.0{\mathrm{cm}}^2$ is the surface area of a skate and $g$ is the gravitational acceleration constant. (a) Compute the decrease in freezing temperature of water caused by this applied pressure. (b) Is this pressure sufficient to melt ice?

Global warming of the oceans. The oceans on Earth weigh $1.37\times {10}^{21}\mathrm{kg}[9]$. If global warming caused the average ocean temperature to increase by $1^{\circ }\mathrm{C}$, what would be the enthalpy increase $\mathrm{\Delta }H?$